The present invention relates to a method of performing digital subtraction angiography (DSA) and more specifically to a method of performing dual energy digital subtraction angiography.
In the past, temporal or time subtraction has been utilized to enhance images obtained in digital subtraction angiography performed with low-energy X-ray beams. However, this method is plagued by misregistration artifacts due to patient motion.
This problem was overcome by the use of dual energy digital subtraction angiography which utilized both a low-energy X-ray beam and a high-energy X-ray beam. However, the signal to noise ratio (SNR) of dual energy DSA is substantially lower than that of the temporal subtraction DSA method due to the weighted subtraction and the high noise level associated with the high-energy image.
It is an object of the present invention to provide a method of performing dual energy DSA which optimizes the signal to noise ratio with respect to patient X-ray exposure.